// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_
#define CC_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_

#include "cc/base/cc_export.h"

#include "ui/gfx/geometry/rect.h"

namespace cc {

namespace proto {
    class LayerStickyPositionConstraint;
}

struct CC_EXPORT LayerStickyPositionConstraint {
    LayerStickyPositionConstraint();
    LayerStickyPositionConstraint(const LayerStickyPositionConstraint& other);

    bool is_sticky : 1;
    bool is_anchored_left : 1;
    bool is_anchored_right : 1;
    bool is_anchored_top : 1;
    bool is_anchored_bottom : 1;

    // The offset from each edge of the ancestor scroller (or the viewport) to
    // try to maintain to the sticky box as we scroll.
    float left_offset;
    float right_offset;
    float top_offset;
    float bottom_offset;

    // The layout offset of the sticky box relative to its containing layer.
    // This is used to detect the sticky offset the main thread has applied
    // to the layer.
    gfx::Point parent_relative_sticky_box_offset;

    // The rectangle corresponding to original layout position of the sticky box
    // relative to the scroll ancestor. The sticky box is only offset once the
    // scroll has passed its initial position (e.g. top_offset will only push
    // the element down from its original position).
    gfx::Rect scroll_container_relative_sticky_box_rect;

    // The layout rectangle of the sticky box's containing block relative to the
    // scroll ancestor. The sticky box is only moved as far as its containing
    // block boundary.
    gfx::Rect scroll_container_relative_containing_block_rect;

    void ToProtobuf(proto::LayerStickyPositionConstraint* proto) const;
    void FromProtobuf(const proto::LayerStickyPositionConstraint& proto);

    bool operator==(const LayerStickyPositionConstraint&) const;
    bool operator!=(const LayerStickyPositionConstraint&) const;
};

} // namespace cc

#endif // CC_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_
